Having had plenty of practice, and some tips early on from seasoned users, I find the Akto works well for me most of the time. Assuming the ground is cooperative, in the event of a thunderstorm or midge attack, I can get it pitched in about a minute or so and dive in, and tweak the tension later without moving the pegs, which is great. And of course it's lovely and warm, and has no fear of strong wind. Headroom, on the other hand, is best described as 'adequate' - the Bella looks like a real improvement in that regard, if you want to do more in a sitting position than just get changed.
Obviously a free-standing tent is a huge win when the ground isn't level or peg-friendly. Or if you need to relocate to a different part of the field for hydrologial or entomological reasons.
Only briefly being a car-owner, I've not really used pop-up tents, other than the
BHPC's timing tent, which works well for that specific use-case (keeps sun and rain off the electronics, fast pitching on ground that isn't always receptive to pegs, standing room, visibility out three sides).